Ignition cut-off device



July 24, 1956 P. A. E. LEWIS 2,755,298

IGNITION CUT-OFF DEVIC E Filed NOV. 4, 1953 FIGURE FIGURE 2 FIGURE 3 FIGURE 5 FIGURE 4 INVENTOR;

United States Patent IGNITION CUT-OFF DEVICE Pleasant A. E. Lewis, Austin, Tex. Application November 4, 1953, Serial No. 390,206 1 Claim. (Cl. ZOO-61.52)

This invention relates to safety devices for cutting off the current to an engine when the vehicle on which it is mounted has tilted beyond a chosen degree. its principal object is the provision of an extremely simple device of the kind which while equally efiicient as the more expensive switches can be constructed at quite low cost.

A further object of the invention is to provide a simple automatic safety cut-ofl. device for use on tractors which consist merely of an elonated runway, preferably tubular, a ball, and an insert snugly fitting the cage or runway so as to confine the ball, and having in it one or more electrical conductors which may lead to a chosen portion of the ignition system of the tractor, either to the spark plugs, the distributor, a magnet or any other portion which would serve to cut the current to the motor when the circuit was bridged by movement of the ball.

A further object of the invention is to provide a simple method of attaching a tubular ignition cut-off device to a tractor which bracket or other similar fastener will furnish the sole support for the device so the latter may readily be adjustable to any chosen angle which may be desired.

In the drawings:

Figure l is a central section;

Fig. 2 is an end view of a slightly modified form;

Figure 3 show the device fastened to a vehicle and showing the connections to the spark plugs and distributor;

Figure 4 shows a tilted tractor in which the device has operated;

Figure 5 shows a tractor in normal position with the cut-off device inoperative.

in selecting a cage or runway for an electrically conducting ball 2, I prefer to use, as being the cheapest object readily available, a simple metal cylinder 1, closed at one end and open at the other. The material of which the cylinder is made is quite immaterial and it may be plastic especially whenever that material is cheaper than the metal tube shown. The ball, as indicated in the drawings, is slightly smaller than the inside of the cylinder 1 and so is free to roll as far as is permitted by the insert 3. This insert is preferably of rubber and should be nonconductive. While it may be secured to the cylinder 1 by a threaded engagement or by one or more set screws, it is my preference that the insert 3 shall fit within the cylinder 1 forming a stopper, so-to-speak, extending well into the cylinder 1 and also fitting rather snugly the outside of the cylinder. The annular recess in which the cylinder end is received should be deep enough so there is no tendency of the margin to gap. The face of the insert within the cylinder is concave and preferably spherical, as shown at 5.

The insert has one or more elongated holes therethrough in which conducting members 4 are frictionally held. These conducting members may be metal rods, for example, slightly headed on the inside and projecting beyond the insert on the outside but are preferably copper tubes, as shown in Figure 2, the advantage of 2,756,298 latented July 24, 1956 the tube being that they receive nicely and firmly a wire such as 6 leading to one of the spark plugs 8 or to the distributor 9. The tubes, as in the case of the rods, are slightly headed on the inside, as best seen in Figure 1, so that when five of these conducting members are used, the ball 2 will engage all five of the members 4 simultaneously. Should the conducting members 4 be solid rods rather than hollow tubes, as preferred, a simre clip of any well known type can be added to the exposed ends for ready reception of the ignition wires.

The operation of the device seems obvious from the description. The device of Figure 1 denoted as a whole by the numeral 7 is received in a bracket 10 which can be moved up or down in an arcuate slot cut in the panel of the tractor and may be secured at any chosen angle merely by fastening the two thumb nuts. It will be noted that the bracket then forms the sole support for the de vice 7. As long as the tractor is in the position shown in Figure 5, the ball 2 is at the closed end of the cylinder 1 but when the tractor has gotten into such a position that an upset seems imminent, the closed end of the cylinder is raised above the insert and the ball 2 promptly rolls to a position to kill the engine, short circuiting all five of the conducting members imbedded in the rubber closure. In the form shown four of the five conductors are connected individually to spark plugs and the fifth to ground.

What I claim is:

An ignition cut-off device adapted to be secured in a tilted position to a tractor, comprising a cylindrical tube having when in such tilted inoperative position a lower closed end and an upper open end; an electrically conducting ball of slightly less diameter than the inside of the tube to roll freely therein; a rubber tube-closing member with a cylindrical head of larger diameter than the outside of the tube, and an integral central cylindrical portion extending from the head to fit within the tube to a depth greater than the radius of the ball, said tubeclosing member having an annular groove many times deeper than its radial dimension between the head and the central portion with coaxial smooth surfaces to receive snugly and protect the open end of the tube as the tube closing member is slid longitudinally on the tube, the end of the central portion within the tube having a concave spherical face of a radius equal to the radius of the ball; and in excess of two spaced conductors adapted to be connected to the tractor spark plugs, passing completely through the rubber tube-closing member, parallel to the axis thereof and extending equal distances beyond said spherical face, whereby when excessive tilting movement of the tractor reverses the tilt of the device secured thereto, the ball roll from the closed end of the tube and will simultaneously make contact with all of the several conductors and thus stall the tractor engine.

References Cited in the file of this patent UNITED STATES PATENTS 1,391,239 Broad Sept. 20, 1921 1,611,219 Minninger Dec. 21, 1926 1,633,386 Rutledge June 21, 1927 1,644,443 Parks Oct. 4, 1927 1,658,013 Armstrong et a1. Jan. 31, 1928 1,662,381 Eynon Mar. 13, 1928 1,761,681 Reis et al. June 3, 1930 2,122,921 Sands July 5, 1938 2,208,841 Gillespie July 23, 1940 2,235,275 Winning Mar. 18, 1941 2,344,014 Allison Mar. 14, 1944 2,486,965 Milster Nov. 1, 1949 2,545,629 Posey et al Mar. 20, 1951 

